Nemanja ultimately went to Mount Athos, where he became a monk and took the name of Simeon, joining his youngest son (later known as Saint Sava), who had already become the first archbishop of the Serbian Orthodox Church.
In 1163, Emperor Manuel I Comnenus came to Niš with the army via Serdica (Sofia), where, according to John Kinnamos, he decided "to deal with things concerning Serbia".
At that time, Serbia was ruled by the Grand Župan Desa, an ally of Stephen III in the Hungarian dynastic conflicts, and thus an opponent of Manuel.
[citation needed] The Byzantines also had success in a campaign in Italy where they captured an important seaport on the west coast of the Adriatic, Ancona.
Venice, which had previously turned to Byzantium for help during the conquest of Friedrich Barbarossa in northern Italy, changed its attitude towards the Byzantines for fear of losing the Adriatic.
[citation needed] As the ideal candidate of Venice and Hungary among the Serbs appeared Nemanja, when his brothers and, above all, Tihomir imprisoned him in a cave near Fortress Ras.
[citation needed] Nemanja probably hoped that he would take the place of Desa, as the former representative of the pro-Greek party, while Emperor Manuel brought his eldest brother Tihomir to the throne.
According to Arnold of Lübeck on that road, near fortress Ravno, in March 1172, the Serbs carried out a night attack on the camp of Western knights and pilgrims led by Henry the Lion accompanied by the Byzantines.
[citation needed] The Kingdom of Hungary also wanted to join the fight against Byzantium, and the Holy Roman Empire of Frederick Barbarossa (1152–1190), also supported this alliance.
The Byzantine emperor accepted his humility, agreeing to the renewal of vassal obligations and leaving Nemanja in the position of grand zoupan.
The final part of this episode took place in Constantinople, where Nemanja was taken as a slave in Manoel's triumphal procession, while the gathered people ridiculed him.
"[15] The Byzantine emperor Manuel Comnenus returned Nemanja to the position of Grand Župan, and he confirmed to his brothers their areas – Stracimir around the West Moravia and Miroslav Zachlumia.
Upon his return to Serbia, Nemanja turned to consolidating the central government, and forced Tihomir's son and successor Prvoslav to renounce the ruler's claims in his favor.
Serbian detachments were also part of the Byzantine army that was defeated by the troops of the Sultanate of Rum in the battle of Myriokephalon on 17 September 1176 in the gorges of Asia Minor.
The Assembly gathered the entire state leadership, composed of nobles and Bishop Euthymius of Ras, as well as a large number of abbots and monks.
The grand zoupan spared the life of their leader, and he was sentenced to corporal punishment, cutting off his tongue so that he would no longer blaspheme and spread harmful teachings.
[citation needed] After the death of Emperor Manoel on 24 September 1180, the Hungarian king Bela III considered that he had no more obligations to Byzantium.
The following 1181, he launched an offensive against Byzantium and conquered Srem (Sirmium) the northeastern part of the Adriatic coast (Including Zara) and Zemun.
The attack itself was quite clumsily carried out, and both fortresses were defended by experienced military leaders from the time of Emperor Manoel, Alexius Branas and Andronikos Lapardas.
Following the death of Manuel I in 1180, his widow, the Latin princess Maria of Antioch, acted as regent to her infant son Alexios II Komnenos.
Her regency was notorious for the favoritism shown to Latin merchants and was overthrown in April 1182 by Andronikos I Komnenos, who entered the city in a wave of popular support.
The following year, Nemanja launched an offensive on the southeastern Adriatic coast and conquered Byzantine Skadar and besieged Dubrovnik (Ragusa).
[citation needed] In 1185, Andronicus I was killed in Constantinople and the new Byzantine emperor Isaac II Angelos began peace negotiations with the Hungarian king.
The Normans of king William II of Sicily, also in 1185, conquered Dyrrachium and Thessalonica, and embarked on an expedition to Constantinople, but they lost discipline due to large-scale looting, so the Byzantines easily defeated them in the battle of Demetritzes near Lower Struma.
In October 1185, in the Lower Danube, in northern Bulgaria, an uprising began, led by the brothers Peter and Ivan I Asen, one of the reasons for which was an extraordinary tribute that Emperor Isaac II ordered to be collected for his wedding.
A large crusader army led by Holy Roman Emperor Frederick Barbarossa marched in 1189 from Buda through Belgrade and Niš to Adrianople and Constantinople.
At the same time, Byzantine Emperor Isaac II Angelos launched a punitive expedition against the Serbs, and Nemanja was defeated in the battle at South Morava (1191).
In November 1192, on the way to Venice, from Acre via Byzantine Corfu to the southeastern Adriatic coast on the small island of Lokrum near Dubrovnik (Ragusa), Richard I arrived incognito as an ordinary knight or pilgrim, where he revealed that he is the King of England.
In April 1195, the father-in-law of Stefan Nemanjić, Alexius III Angelus (1195–1203), overthrew his brother Emperor Isaac II and took power.
[citation needed] Knowing his death was near in his 86th year, Simeon asked to be placed on a mat in front of the icon of the Virgin Hodegetria with a stone for his pillow.